A total of 379 species of mammals have been recorded in Australia and surrounding continental waters; 357 indigenous and 22 introduced. 83% of mammals are endemic to Australia. A unique feature of Australia's fauna is the relative scarcity of native placental mammals. Consequently the marsupials—a group of mammals that raise their young in a pouch, including the macropods, possums and dasyuromorphs—occupy many of the ecological niches placental animals occupy elsewhere in the world. Australia is home to two of the 5 known extant species of monotremes.

The settlement of Australia by Indigenous Australians between 48,000 and 70,000 years ago [3] (research in 2011 using DNA suggesting an arrival around 50,000 years ago),[4] and by Europeans from 1788, has significantly affected the fauna. Hunting, the introduction of non-native species, and land-management practices involving the modification or destruction of habitats have led to numerous extinctions. Some examples include the Paradise Parrot, Pig-footed bandicoot and the Broad-faced Potoroo. Unsustainable land use still threatens the survival of many species. To target threats to the survival of its fauna, Australia has passed wide-ranging federal and state legislation and established numerous protected areas.